docs: def filter_by_conditional_statement(self, statement):
          """Filter the Data Collection based on a conditional statement.
  
          Args:
              statement: A conditional statement as a string (e.g. a > 25 and a%5 == 0).
                  The variable should always be named as 'a' (without quotations).
  
          Return:
              A new Data Collection containing only the filtered data
          """
          _filt_values, _filt_datetimes = self._filter_by_statement(statement)
          if self._enumeration is None:
              self._get_mutable_enumeration()
          col_obj = self._enumeration['mutable'][self._collection_type]
          collection = col_obj(self.header.duplicate(), _filt_values, _filt_datetimes)
          collection._validated_a_period = self._validated_a_period
          return collection